Lack of effect of a poster-based intervention to reduce the number of blood culture samples collected.

OBJECTIVE: To reduce the number of blood culture samples collected. PATIENTS AND METHOD: We performed a cluster randomized controlled trial in adult acute care, and subacute care and rehabilitation wards in a university hospital in France. A poster associating an image of eyes looking at the reader with a summary of blood culture sampling guidelines was displayed in hospital wards in the intervention group. The incidence rate of blood cultures per 1000 days during pre- and post-intervention periods was calculated. RESULTS: Thirty-one wards participated in the study. The median difference in blood cultures/1000 days between periods was -1.863 [-11.941; 1.007] in the intervention group and -5.824 [-14.763; -2.217] in the control group (P=0.27). CONCLUSION: The intervention did not show the expected effect, possibly due to the choice of blood cultures as a target of good practice, but also to confounding factors such as the stringent policy of decreasing unnecessary costly testing.

Outcome of patients with streptococcal prosthetic joint infections with special reference to rifampicin combinations.

BACKGROUND: Outcome of patients with streptococcal prosthetic joint infections (PJIs) is not well known. METHODS: We performed a retrospective multicenter cohort study that involved patients with total hip/knee prosthetic joint (THP/TKP) infections due to Streptococcus spp. from 2001 through 2009. RESULTS: Ninety-five streptococcal PJI episodes (50 THP and 45 TKP) in 87 patients of mean age 69.1 ± 13.7 years met the inclusion criteria. In all, 55 out of 95 cases (57.9 %) were treated with debridement and retention of the infected implants with antibiotic therapy (DAIR). Rifampicin-combinations, including with levofloxacin, were used in 52 (54.7 %) and 28 (29.5 %) cases, respectively. After a mean follow-up period of 895 days (IQR: 395-1649), the remission rate was 70.5 % (67/95). Patients with PJIs due to S. agalactiae failed in the same proportion as in the other patients (10/37 (27.1 %) versus 19/58 (32.7 %); p = .55). In the univariate analysis, antibiotic monotherapy, DAIR, antibiotic treatments other than rifampicin-combinations, and TKP were all associated with a worse outcome. The only independent variable significantly associated with the patients' outcomes was the location of the prosthesis (i.e., hip versus knee) (OR = 0.19; 95 % CI 0.04-0.93; p value 0.04). CONCLUSIONS: The prognosis of streptococcal PJIs may not be as good as previously reported, especially for patients with an infected total knee arthroplasty. Rifampicin combinations, especially with levofloxacin, appear to be suitable antibiotic regimens for these patients.

Incidence of anaerobic bacteria in patients with suspected pneumonia in surgical Intensive Care Unit.

BACKGROUND: Few studies have investigated the incidence of pulmonary anaerobes in a specific population in surgical Intensive Care Unit (ICU). The objective of this work was to determine the incidence of anaerobes in surgical ICU patients with suspected pneumonia. METHODS: This was a prospective observational, single-center study. Analysis was based on data collected over 30 months from the surgical ICU of a tertiary care hospital (Rouen University Hospital), including data on risk factors for anaerobes in the lungs. Patients with suspected pneumonia (community-acquired or nosocomial) were included. Bacteriological sampling was performed by protected distal bronchial sampling (PDBS) with minilavage under bronchoscopy. Aerobic and anaerobic cultures were performed for each sample. Clinicians were only aware of aerobic results. Univariate and multivariate statistical analysis compared groups with and without anaerobes. RESULTS: A total of 134 samples were obtained from 117 patients. Surgery was performed on 74 patients (63.2%), within 24 hours of admission. Fifty-four patients (46.2%) had a chest trauma and 20 patients (17.1%) were admitted for a digestive pathology. Average age was 53.6±20.9 years and sex ratio was 5.9 (100 men/17 women). Average SAPS II was 41.6±15.1, median length of ICU stay was 23 days (25th percentile=13, 75th percentile=33), and median duration of mechanical ventilation was 21 days (25th percentile=11, 75th percentile=28). Mortality rate in ICU was 14.5%. After sampling, diagnosis of pneumonia was confirmed in 70 cases (52.2%). Anaerobe cultures were positive in 11 samples taken from 11 different patients (overall incidence 8.2%). Aerobic bacteria were also involved in 9 patients (81.8%). In univariate analysis, enteral feeding (P=0.02) and absence of catecholamines at time of sampling (P=0.003) were significantly associated with the presence of anaerobes in PDBS. Enteral nutrition was also found to be a risk factor in multivariate analysis (OR=11.8, 95% CI [1.36 to 102.4] P=0.025). Prior antianaerobic antibiotic treatment was not a protective factor. No difference was observed regarding the notion of aspiration, survival, total length of stay and duration of mechanical ventilation, or evolution of pneumonia between the two groups. CONCLUSION: Our study demonstrates the presence of anaerobic bacteria in the lung samples of patients from surgical ICU with an incidence comparable to that found in populations from medical ICU departments. Anaerobic morbidity in our study is in line with recent literature.

[Hypothermia at admission increases the risk of pulmonary contusion's infection in intubated trauma patients]. / L'hypothermie à l'admission augmente le risque d'infection des contusions pulmonaires chez les patients polytraumatisés sous ventilation invasive.

OBJECTIVES: Pulmonary contusion (PC) is common in cases of polytrauma. The aim of this study was to perform a multivariate analysis of risk factors associated with the occurrence of infection in PC and analyze the microbiological epidemiology. PATIENTS AND METHODS: All patients with PC admitted to the intensive care unit (ICU) between January 2002 and December 2006 were included in this retrospective observational study. Patients with penetrating thoracic trauma or those who died in the 48hours following admission to hospital were excluded. Diagnosis of bacterial infection in PC was performed if hyperthermia was associated with a positive quantitative culture (103 colony forming units/mL) on the bronchial sample. Univariate analysis provided statistical difference between variables that were integrated in the multivariate analysis model. Multivariate analysis was then performed to determine the risk factors of bacterial infection in PC. RESULTS: One hundred and seventeen patients were included. The incidence of bacterial infection in PC was 33.3% (39 patients). The most frequently encountered bacteria were Haemophilus sp., Staphylococcus aureus, Enterobacteriaceae, Pseudomonas sp. and Streptococcus sp. According to multivariate analysis, the existence of hypothermia at hospital admission increased the risk of PC infection (OR=2.61; IC 95% [4.2-13.3]). CONCLUSION: In conclusion, PC was infected in 33.3% of cases. The existence of hypothermia was identified as a risk factor. A prospective study is warranted to confirm these results.

Surgical glove bacterial contamination and perforation during total hip arthroplasty implantation: when gloves should be changed.

INTRODUCTION: Double gloving is recommended in orthopedic surgery, notably in total hip arthroplasties (THA) to prevent contamination of the surgical site. HYPOTHESIS: Systematic glove changes during the key phases of hip prosthesis implantation reduce the frequency of occult perforations and bacterial loading of glove surfaces. PATIENTS AND METHODS: During 29 THA implantation procedures, we evaluated the bacterial contamination of the outer glove surface and its perforation rate. Contaminations were sought by placing the gloved fingertips on blood geloses (incubation, 48 h at 37°C), and perforations were sought using a water test (NF EN 455-1). RESULTS: One intervention was excluded from the study because an initial contamination was detected, leaving 28 cases analyzed. Fifteen interventions (53.6%) presented contaminated geloses (26 contaminated glove changes for 3.38% of the gloves used). These contaminations were found on the gloves of all of the gloved personnel, with no distinction as to the right or left side. Thirty-eight percent of the contaminations occurred during joint reduction, whereas the other surgical stages grouped 15-26% of the contaminations (P<0.05). Twenty-nine bacteria were identified: 62% coagulase-negative staphylococci (16% of which were methicillin-resistant). Twenty-eight perforations were identified (3.5% of the gloves used), 67.8% of which were located on the operator and 64.3% on the dominant side. Eighty percent of the perforations occurred during the "surgical incision" and the "cup and stem implantation" stages (respectively, 5.0% and 5.5% of the gloves used during the surgical time) (P<0.05), without being associated with an increased risk of bacterial contamination. At the 12-month clinical follow-up, no infectious complications were found. On the gloves worn by the 20 surgical team members contaminated during these 28 surgical procedures, replacing contaminated gloves with new sterile gloves rendered all the bacteriological samples of the subsequent surgical stages negative in 16 cases (80%). DISCUSSION: Increasing the number of outer glove renewals, notably during certain surgical stages at risk for contamination (prosthesis reduction) or perforation (surgical incision/femoral cementing) can reduce the risk of contamination and perforation. The bacteria isolated suggest a cutaneous origin. Regularly changing gloves has resulted in a sterile state in 80% of cases. LEVEL OF EVIDENCE AND TYPE OF STUDY: Level III prospective diagnostic study.

[Does pulmonary contusion expose to the risk of Streptococcus pneumoniae infections? Results of an experimental study]. / La contusion pulmonaire expose-t-elle au risque de prolifération bactérienne à pneumocoque ? Résultats d'une étude expérimentale.

OBJECTIVE: To create a reliable and reproducible model of pulmonary contusion (PC) in rats in order to evaluate the influence of PC on bacterial lung proliferation. STUDY DESIGN: Experimental. ANIMALS: Male albino CD rats. METHODS: Animals were anesthetized and a PC was performed using a spring-loaded metal bar. The existence of an isolated right PC was confirmed by macroscopic, histological and radiological analysis. This model was used to compare four randomized groups of animals. These were either injured or only anesthetized and inoculated with a pneumococcal solution concentrated in 2 or 4 log(CFU/mL). The animals' lungs were collected for microbiological culture at 24 hours. The bacterial count evolution per gram of lung was the primary endpoint. RESULTS: Twelve rats were needed to validate the model, 84 to determine the morbidity and mortality and its reproducibility and 66 to assess the intra-pulmonary bacterial proliferation. The PC obtained was unilateral and isolated in 95% of cases. Mortality rate was 43%. For a low initial inoculum concentration (2 log [CFU/mL]), there is bacterial overgrowth in the PC group versus the no-PC group (P=0.0017). This difference was not found when the inoculum was more concentrated. CONCLUSION: This experimental model is reliable and reproducible. The initially high mortality seems to decrease with the experience of operators. The CP significantly increases intra-pulmonary bacterial proliferation when the inoculation is low. A high inoculum neutralizes the effect of CP. These results suggest that enhanced prevention of micro-inhalation could be beneficial in cases of CP.

Bacterial colonization after tunneling in 402 perineural catheters: a prospective study.

BACKGROUND: Bacterial colonization of peripheral nerve catheters is frequent, although infection is relatively rare. With central venous catheters, the tunneling of the catheter into the subcutaneous tissue significantly decreases catheter colonization and catheter-related sepsis. We evaluated the incidence of bacterial colonization in adult patients with tunnelized perineural nerve catheters. METHODS: Peripheral nerve catheters placed under sterile conditions for postoperative analgesia were evaluated prospectively. After removal, they were analyzed for colonization. Quantitative culture was used as described by Brun-Buisson for intravascular catheters. The site of insertion was monitored daily for any signs of infection. RESULTS: Four-hundred-two patients were included in the study during a 2-yr period. The mean duration of peripheral nerve catheters was 48 h (47-50.4). Positive culture occurred in 25 catheters, indicating that the incidence of colonization was 6.22% (3.8-8.5). The microbiological analysis of the catheter tip cultures revealed coagulase-negative staphylococci in 72%. Twenty-two catheters of 25 catheters each had one microorganism, and for three catheters, two microorganisms were identified. No infection was found in any patient. CONCLUSION: The incidence of perineural catheter colonization is low with subcutaneous tunneling. Controlled randomized studies are warranted to determine whether this procedure decreases the risk for infection.

Mycoplasma hominis wound infection after a vascular allograft.

Cases of Mycoplasma hominis infections after allograft are rare. We report a case of M. hominis wound infection after a vascular allograft. The allograft was positive before having any contact with the recipient, and our investigation suggests that M. hominis may have been transmitted from the donor to the recipient. It is not clear, however, whether specific diagnosis of M. hominis should be performed on tissue before grafting in order to prevent such donor-to-host transmission.

Recurrent recovery of Pseudomonas oryzihabitans strains in a karstified chalk aquifer.

Pseudomonas oryzihabitans is an uncommon pathogen that may cause catheter-associated infections, particularly in immunocompromised patients. Although it has been isolated from environment, the source of human infection is not well documented. In the present study, 14 isolates of P. oryzihabitans were recovered over a 28-month period from a karstified chalk aquifer, allowing to advance that distributed natural water could be a source of contamination. Microbiological analyses showed that the bacterium was mainly associated with suspended particulate matters. To investigate the clonality of P. oryzihabitans environmental isolates, 16S rRNA gene sequencing, antibiogram and randomly amplified polymorphic DNA (RAPD) typings were performed. Results demonstrated (i) the presence of at least three clones within the aquifer and (ii) that the presence of the bacterium in groundwater is not only the result of a biofilm bloom but also of an exogenous contamination.

[Extensive purpura and septic schock in two patients with Capnocytophaga canimorsus]. / Purpura extensif au cours d'un choc septique à Capnocytophaga canimorsus: deux observations.

INTRODUCTION: Capnocytophaga canimorsus is a Gram negative bacillus present in oral flora and in saliva of dogs and cats. It can be responsible for septicaemia and meningitides in some patients after dog or cat bite two patient with a septic shock due to C. canimorsus, who presented with an extensive pupura are reported. CASE REPORT: A 50 year-old man with a past history of splenectomy was referred to an emergency department for a shock with vomiting, abdominal pain and generalized ecchymotic purpura culture samples isolated C. canimorsus in peritoneal fluid. Purpura occurred secondary to a disseminated intravascular coagulation. Despite intensive care and major antibiotherapy, the patient rapidly died. Four days previously, the patient administered pills in his dog mouth. The second patient was a 39 year old alcoholic man who was hospitalised for vomiting and septic shock witch occurred 24 hours after a dog bite. He presented with a livido and a diffuse purpura associated with necrotic lesions. Cultures of blood samples isolated C. canimorsus. CONCLUSION: These severe infections due to C. canimorsus should be avoided by the routine use of early antibiotherapy with amoxicilline and clavulanic acid in patients with dog or cat bite, particularly if patient with associated debilitating disorders.

[An unusual aetiology for septic shock: Capnocytophaga canimorsus. Is always dog man's best friend?]. / Un choc septique d'étiologie inhabituelle: Capnocytophaga canimorsus. Le chien est-il toujours le meilleur ami de l'homme?

The mortality of overwhelming postsplenectomy infections (OPSI) is significant (50 to 80 percent). Capnocytophaga canimorsus belongs to the normal oral flora of dogs and cats. It is seldom responsible for human infections, but its prognosis is bad (about 30 percent of overall mortality), especially in asplenic patients. We report a case of a splenectomized patient who suffered from communal septic shock due to C. canimorsus septicaemia. The course of events was rapidly fatal. Diagnosis and mode of contamination were determined only a few weeks after the patient's death. This late microbiological diagnosis is due to a slow growth of C. canimorsus in vitro.

[Osteoarticular infection in children: evaluation of a diagnostic and management protocol]. / Infections ostéo-articulaires de l'enfant: étude de deux séries consécutives et évaluation d'un protocole de diagnostic et de traitement.

PURPOSE OF THE STUDY: The purpose of this study was to evaluate a diagnostic and management protocol for osteoarticular infection in children which was developed at the Rouen University Hospital in 1993. We studied the technical aspects of the protocol allowing improved certain diagnosis and bacteriological documentation as well as the reduction in intravenous treatments and hospital stay. MATERIAL AND METHODS: Two successive series were compared. The first constituted from May 1984 to February 1992 was a retrospective series of 106 children with osteoarticular infections. The second series was prospective an included 104 children with osteoarticular infection treated after institution of the protocol (January 1995 to December 1998). All children were treated in the same unit. Files were reviewed at a minimum follow-up of 18 months following the end of treatment. We analyzed: clinical, biological, and radiological data at admission; elements of the bacteriological study and their contribution to identification of the causal agent; duration of intravenous antibiotic therapy; total duration of antibiotic therapy, and hospital stay; complications and sequelae. RESULTS: After institution of the protocol, we observed significant progress: certain diagnosis of acute osteomyelitis improved from 67% to 85% after institution of a more comprehensive diagnostic program; bacteriological identification improved from 37.5% to 72.2% for acute osteomyelitis and from 41.6% to 59.5% for septic arthritis, with a growing number of recognized cases of Kingella kingae infections causing acute osteomyelitis (n=2) or septic arthritis (n=4) due to technical progress in sampling and culturing. Mean duration of intravenous antibiotic therapy (15 days versus 9.95 days), mean duration of total antibiotic therapy (47.3 versus 33.8 d) as well as length of hospital stay (17.5 d versus 12.5 d) were significantly improved. The shorter antibiotic therapy did not led to any supplementary morbidity. CONCLUSIONS: A systematic bacteriological diagnostic protocol has enabled an improvement in treatment and hospitalization. The protocol has been further updated and simplified in light of these findings and observations of insufficiencies, taking into account recent data in the literature and epidemiological features of osteoarticular infection in children.

[Kingella kingae osteoarticular infections in children. A report of a series of eight new cases]. / Les infections ostéoarticulaires à Kingella kingae chez l'enfant. A propos d'une série récente de huit cas.

UNLABELLED: Kingella kingae is a Gram-negative bacillus which belongs to the Neisseriaceae family. Its involvement in osteoarticular infections is relatively recent. METHODS AND RESULTS: We report eight cases of Kingella kingae osteoarticular infections that have been diagnosed at the paediatric surgical centre of Rouen University Hospital since October 1995. Six boys and two girls (mean age: 30.6 months) presented with osteomyelitis in six cases and arthritis in two. Only 75% of patients had a fever at time of diagnosis. The biological findings were slightly modified. All samples were obtained from blood, bone or joint fluid. These samples were systematically inoculated into a blood culture tube. Positive Kingella kingae culture was achieved in seven local samples and in one blood culture. All children received two antibiotics via intravenous injection while waiting for the bacteriologic results. Later, the antibiotic treatment (amoxycillin) was given per os. The mean duration of treatment was 33 days. Patients were given intravenous treatment for a period of only ten days. Six patients were followed up for a period of more than 18 months and outcome was always uneventful. DISCUSSION: Kingella kingae is usually present in the nasopharyngeal mucosa and spreads in the blood due to various infections. Different types of Kingella kingae infection have been reported with a large frequency of osteoarticular infection. CONCLUSION: This type of infection does not present any unusual characteristics as compared to other osteoarticular infections. Because of its antibiotic sensitivity treatment duration could be reduced. Kingella kingae is a fragile microbe and its culture is often difficult; therefore, it is important to use blood culture tubes to inoculate joint fluid and bone samples.

PCR-Based assay for discrimination between invasive and contaminating Staphylococcus epidermidis strains.

The discrimination between Staphylococcus epidermidis strains that contaminate and infect blood cultures is a daily challenge for clinical laboratories. The results of PCR detection of putative virulence genes were compared for contaminating strains, sepsis-related strains, catheter strains, and saprophytic strains. Multiplex PCR was used to explore the atlE gene, which is involved in initial adherence, the intercellular adhesion gene cluster (ica), which mediates the formation of the biofilm, and the agrA, sarA, and mecA genes, which might contribute to the pathogenicity of S. epidermidis. Whereas the atlE, agrA, and sarA genes were almost ubiquitously amplified, the ica and mecA genes were detected significantly more in infecting strains than in contaminating strains (P

Bacterial resistance of refrigerated and cryopreserved aortic allografts in an experimental virulent infection model.

PURPOSE: The bacterial resistance of refrigerated and cryopreserved aortic allografts in a highly virulent infection in a dog model was studied. METHODS: The infrarenal aorta of 12 dogs was replaced with either a cryopreserved aortic allograft (group I, n = 6) or a refrigerated aortic allograft (group II, n = 6) in infected sites. Allografts were harvested from dogs and stored for 1 week, either by cryopreservation (-140 degrees C) or refrigerated method (4 degrees C), in a preservation medium. At the time of implantation, induction of infection was achieved with an infected piece of knitted Dacron placed just beneath the allograft. The Dacron was contaminated in vitro by soaking it in a solution with Staphylococcus aureus PR209. All 12 dogs received no adjunct antibiotic or antithrombotic therapy. Four weeks after implantation, the animals were killed to recover the grafts for bacteriological and histological analyses. Bacterial results were expressed as colony-forming units (CFU)/cm2 of graft material. RESULTS: In group I, only one allograft grew bacteria at 2. 16 x 10(6 )CFU/cm2, with a blood culture positive for S aureus. In group II, one dog died at 3 weeks from a false septic aneurysm rupture, all the allografts were infected (P <.05) with a mean bacterial count of 9.41 +/- 6.8 x 10(4) CFU/cm2, and three blood cultures were positive for S aureus. The patency of the grafts was analyzed at the time of recovery. Three laminar thrombi without occlusion were present in group I; none were present in group II. A better preserved endothelium in group I was revealed by means of histologic analysis staining with factor VIII antibody before implantation. After 4 weeks of implantation in the infected site, infected allografts presented polynuclear infiltrates in the media with a high degree of inflammatory reaction, and endothelial recovery was more significant in group I, with numerous young plump cells. CONCLUSION: This study demonstrates that cryopreserved allografts implanted in infected sites in a dog model can produce greater bacterial resistance.

Evidence for nasal carriage of methicillin-resistant staphylococci colonizing intravascular devices.

Nasal surveillance cultures were performed for 54 patients exhibiting >/=10(3) CFU of methicillin-resistant coagulase-negative staphylococci per ml in central venous catheter (CVC) rinse cultures over a 6-month period. Forty-two of the nasal cultures yielded growth of methicillin-resistant coagulase-negative staphylococci, and 33 of the 42 cultures contained organisms that belonged to the same species as the CVC isolates. Of the 33 same-species isolates, 20 appeared to be identical strains by pulsed-field gel electrophoresis analysis. These data suggest that measures should be taken to reduce cross-contamination between the respiratory tract and intravascular devices. However, the potential interest in detecting methicillin-resistant coagulase-negative staphylococcus carriage in high-risk patients is hampered by the lack of sensitivity of nasal surveillance cultures.

Comparison of ATB staph, rapid ATB staph, Vitek, and E-test methods for detection of oxacillin heteroresistance in staphylococci possessing mecA.

The performance characteristics of the E-test (AB Biodisk, Solna, Sweden), the ATB Staph, the Rapid ATB Staph, and the Vitek GPS-503 card (bioMérieux, La Balme Les Grottes, France) methods for the detection of oxacillin resistance in a collection of staphylococci with a high proportion of troublesome strains were evaluated. Sixty-four Staphylococcus aureus strains and 76 coagulase-negative staphylococcal strains were tested. All strains were mecA positive and were characterized by the oxacillin agar screen plate test; 75 (53.6%) were found to be heterogeneous by a large-inoculum oxacillin disk diffusion assay, and oxacillin MICs for 89 (63.6%) were < or = 32 microg/ml. Three (4.7%) S. aureus strains and 25 (32.9%) coagulase-negative strains were classified as susceptible by the E-test, as defined by the National Committee for Clinical Laboratory Standards (NCCLS) oxacillin breakpoint (MIC < or = 2 microg/ml). The ATB Staph method failed to detect oxacillin resistance in 7 (11%) S. aureus isolates and 32 (42.1%) coagulase-negative isolates. The MICs for all but six of these discrepant isolates were < or = 16 microg/ml. The Rapid ATB Staph method was tested against S. aureus strains only and yielded 15 (23.4%) false-susceptible results for strains for which the MICs were < or = 32 microg/ml. The Vitek system was the best-performing system, since it failed to detect oxacillin resistance in only 3 (4.7%) S. aureus strains and 15 (19.7%) coagulase-negative strains, the MICs for all of which were < or = 2 microg/ml. These data indicate that (i) the performance of the two ATB Staph systems can be limited when the prevalence of borderline-heteroresistant staphylococci is high and (ii) the unreliability of the E-test and the Vitek methods for detecting resistant coagulase-negative strains might be reduced by the potential revision of the oxacillin breakpoint currently recommended by the NCCLS.